Overheating under load

[marek4792]

so recently I noticed that my truck a Volvo VN780 with a cm870 isx with the mandate removed (loaded and empty, hot or cold outside) when under load my coolant temperature climbs quicker than usual, and when accelerating up to highway speed (70mph at 1500rpm) the temperature will already be up to 210 and the fan will kick on and drop it down 10 degrees, but it will come right back up and repeat until the road levels out or i back off the pedal even then the temperature does not seem to come back down right away. My oil temperature stays at 225 and climbs up to 235 but i see up to 245 during a long pull. I had a new thermostat put in last week the radiator and intercooler were replaced with new oem in February, my shop claimed the water pump was changed before i took ownership of the truck. I did put a hand over the front end of the truck with the fan running and noticed that air doesn't seem to flow as much through the condenser opposing to the lower part where it's just the intercooler and radiator only? I still maintain the same fuel mileage 6.1 from Michigan to New Jersey at 79,000 lbs pulling reefer and I am not losing any coolant and no chocolate milkshake in the oil. Thanks and happy fathers day to all the dads out here!

[scottydogtruck]

Having the same problem with my 2011 Pete 387 with a ISX15 CM2250.........my rad and CAC are OEM, and never been changed. New thermostat recently tho.......

[Big D]

If you think it's a airflow problem,you can spray condenser and everything you can get to front and back with purple power or degreaser of your choice. Let it set a few minutes then start truck and turn fan on,set idle as high as it will go and start rinsing the degreaser out. If that helps then you get to pull everything apart to clean it.

[marek4792]

Do you think it could it could also be a worn water pump because it takes like maybe 10-20 minutes to warm up or perhaps a blocked heater core, I ask because this issue started to happen once I got loaded out of Florida and where I was picking up the lot and trail getting to it was all sand

[Rawze]

(06-19-2016 )marek4792 Wrote:  so recently I noticed that my truck a Volvo VN780 with a cm870 isx with the mandate removed (loaded and empty, hot or cold outside) when under load my coolant temperature climbs quicker than usual, and when accelerating up to highway speed (70mph at 1500rpm) the temperature will already be up to 210 and the fan will kick on and drop it down 10 degrees, but it will come right back up and repeat until the road levels out or i back off the pedal even then the temperature does not seem to come back down right away. My oil temperature stays at 225 and climbs up to 235 but i see up to 245 during a long pull. I had a new thermostat put in last week the radiator and intercooler were replaced with new oem in February, my shop claimed the water pump was changed before i took ownership of the truck. I did put a hand over the front end of the truck with the fan running and noticed that air doesn't seem to flow as much through the condenser opposing to the lower part where it's just the intercooler and radiator only? I still maintain the same fuel mileage 6.1 from Michigan to New Jersey at 79,000 lbs pulling reefer and I am not losing any coolant and no chocolate milkshake in the oil. Thanks and happy fathers day to all the dads out here!

What kind/style of "Mandate removal" do you have?

What is your boost and pyro getting up to in a hard pull?

[marek4792]

I had Unilevers do my removal, up the torque from 500/1650ftlbs to 500/1850ftlbs abit and replaced the timing and metering actuators per his recommendations and I have hadnt had any problems with it, my boost during a hard pull stays around 30-32lbs my pyro is acting up so I don't know for sure the sensor works normally up to 700degrees but drops off to 0 like a bad connection

[Rawze]

(06-19-2016 )marek4792 Wrote:  I had Unilevers do my removal, up the torque from 500/1650ftlbs to 500/1850ftlbs abit and replaced the timing and metering actuators per his recommendations and I have hadnt had any problems with it

Do you have a boost and pyro gauge? -- If not, your flying blind there.

Higher than normal coolant temps and oil temps can be a lot of things.

I know of one truck that overheated easily since the guy owned the truck. Had it to several shops, they changed so much stuff that it was not funny. -- The guy showed up over here and as soon as I opened his hood, I could see that the engine fan itself was installed backwards and it was pushing air forward instead of pulling it through the radiator.

Standing on the drivers side and looking at the very edge of the fan blade on that truck is what gave it away ...


Just trying to say that sometimes the obvious is overlooked easily.

[marek4792]

I overlooked the 2nd part of your post and updated it but yes I agree sometimes it the stupid obvious things that get you